Room temperature NO2 sensing performance of ZnO nanorods modified VO2(B) nanosheets interlaced self-assembly nanoflowers

Abstract

In this work, VO₂(B) nanoflower–ZnO nanorod composite structures were proposed to enhance the sensing performance of VO₂(B) nanosheets to NO₂ at room temperature. VO₂(B) nanoflower composed of nanosheets and ZnO nanorods composite structures with uniform size were synthesized by a combination method of hydrothermal and water bath. The effects of hydrothermal time on the morphology and gas-sensitive performance of VO₂(B) nanoflowers, and the effect of ZnO content on the room temperature NO₂ sensing performance of VO₂(B) nanoflowers–ZnO nanorods composite structures were investigated. The VO₂(B) nanoflower–ZnO nanorod composite structure shows a response of 4.96 to 5 ppm NO₂, with an enhancement of up to 212% compared to VO₂(B) nanoflower. The improvement in NO₂ sensing performance can be attributed to an increase in the specific surface area of VO₂(B) nanoflowers, an increase in the number of homojunctions in VO₂(B) nanoflowers, and a synergistic effect of n–n heterojunction sensitization. Therefore, the activation of VO₂(B) with ZnO may be a promising approach for the design and fabrication of high-performance room temperature gas sensors.